Sahih Bukhari, Chapter: Prayers (Salat)

The Prophet delivered a sermon and said, "Allah gave a choice to one of (His) slaves either to choose this world or what is with Him in the Hereafter. He chose the latter." Abu Bakr wept. I said lo myself, "Why is this Sheikh weeping, if Allah gave choice to one (of His) slaves either to choose this world or what is with Him in the Here after and he chose the latter?" And that slave was Allah's Apostle himself. Abu Bakr knew more than us. The Prophet said, "O Abu Bakr! Don't weep. The Prophet added: Abu- Bakr has favored me much with his property and company. If I were to take a Khalil from mankind I would certainly have taken Abu Bakr but the Islamic brotherhood and friendship is sufficient. Close all the gates in the mosque except that of Abu Bakr.